AAMP Memory leaks detection with Valgrind

Valgrind web site: https://valgrind.org/

Valgrind is supported on Ubuntu out of the box. (On newer MacOS versions requires manual installation)

1. Installing Valgrind using command prompt on Ubuntu VM:
   1. Ubuntu: $ sudo snap install valgrind --classic
   2. After the installation is done execute: $ valgrind --version 
      response should be: valgrind-3.20.0 (or any newer version)
   3. Possible installation issues
      1. getting "valgrind: the 'impossible' happened: IA-64 cache detected?!"
         
         1. Shut down the VM
         2. Open the VM settings and make sure the processors slider is not in the red area
            1. 
2. Preparing the application under test:
   1. To be compiled with -g to include debug info. This is the default mode for simulator, so nothing to do.
3. Running test with Valgrind
   1. Baseline test example
      1. $ valgrind --error-limit=no ./aamp-cli https://bitmovin-a.akamaihd.net/content/MI201109210084_1/mpds/f08e80da-bf1d-4e3d-8899-f0f6155f6efa.mpd
      2. give it some time as running with valgrind is much slower. For best results can run on a powerful workstation
      3. after some test time observing audio and video - execute these commands:
         1. stop
         2. exit
      4. Once the aamp-cli process exits - Valgrind will printout in the console the results.
      5. sample results:
         1. ==2557== 
            ==2557== HEAP SUMMARY:
            ==2557==     in use at exit: 1,922,526 bytes in 15,071 blocks
            ==2557==   total heap usage: 1,458,652 allocs, 1,443,581 frees, 538,978,697 bytes allocated
            ==2557== 
            ==2557== LEAK SUMMARY:
            ==2557==    definitely lost: 23,844 bytes in 266 blocks
            ==2557==    indirectly lost: 80 bytes in 2 blocks
            ==2557==      possibly lost: 416 bytes in 1 blocks
            ==2557==    still reachable: 1,823,418 bytes in 14,074 blocks
            ==2557==         suppressed: 0 bytes in 0 blocks
            ==2557== Rerun with --leak-check=full to see details of leaked memory
            ==2557== 
            ==2557== For lists of detected and suppressed errors, rerun with: -s
            ==2557== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
      6. Detailed test

         1. $ valgrind --leak-check=full --error-limit=no ./aamp-cli <<.mpd URL>>

         2. sample results log: https://wiki.rdkcentral.com/download/attachments/274989296/valgrind.log?api=v2
4. Pass/Fail criteria
   1. Valgrind results will vary based on the usage of the application. 
   2. Make sure to always run the same steps and the same time as the baseline is done when comparing valgrind results with the baseline.
   3. Need to have a baseline report and compare future reports. Due to the nature of the Valgrind reports - not all reported issues are considered as issues. The goal is to make sure the number of issues is not increasing without a reason, and if it is increased - raise a ticket with the delta.
   4. Example: 
      1. check if the number of lost blocks has increased from the baseline run 
         1. definitely lost: 23,844 bytes in 266 blocks
      2. check the remaining output for differences in the identified blocks.
5. Possible cases and areas to be considered when developing the test cases with Valgrind
   1. Can have multiple test cases and use their baseline results for detecting new leaks.
   2. Can have one test running for different time periods to detect memory leaks accumulation
   3. Can use aamp-cli cmd line scripting to assure the same steps are executed every time and the timings are the same between different test runs.
6. Notes:
   1. for building and running aamp to run on a device follow the attached document